cultured pearl

cultured pearl
a pearl induced to form by placement of a grain of sand or another irritating object within the shell of a pearl oyster or mussel.
Also, culture pearl.

* * *

      natural but cultivated pearl produced by a mollusk after the intentional introduction of a foreign object inside the creature's shell. The discovery that such pearls could be cultivated in freshwater mussels is said to have been made in 13th-century China, and the Chinese have been adept for hundreds of years at cultivating pearls by opening the mussel's shell and inserting into it small pellets of mud or tiny bosses of wood, bone, or metal and returning the mussel to its bed for about three years to await the maturation of a pearl formation. Cultured pearls of China have been almost exclusively blister pearls (hemispherical pearls formed between the mussel and its shell), which require addition of a half sphere of mother-of-pearl to create the assembled gem, called a pearl doublet.

      The production of whole cultured pearls was perfected by the Japanese (Japan). The research that led to the establishment of the industry was started in the 1890s by Mikimoto Kōkichi, who, after long experimentation, concluded that a very small mother-of-pearl bead introduced into the mollusk's tissue was the most successful stimulant to pearl production. It possesses the added virtue of providing a pearl entirely of nacreous content. Cultured pearls closely approximate natural pearls. If the covering of nacre is too thin, however, it will deteriorate upon prolonged contact with the acids of the human body and eventually will reveal the mother-of-pearl matrix.

      Once a shore-based activity, pearl farms now generally use a vessel as an operating platform. Immature pearl oyster shells (usually Pinctada fucata or Pteria penguin in Japan and Pinctada maxima in Australia) are reserved in barrels until maturation (2 to 3 years) and, when the shells reach certain size, are implanted with a tiny polished sphere of mother-of-pearl. The implanted oysters are suspended in wire nets from floating rafts or contained in some other way and are tended by divers until they are ready for harvesting; readiness is often determined by X ray.

      Northern Australia established its first pearl farms in the 1960s, principally with Japanese collaboration, and by the mid-1970s were an established industry, producing pearl shell as well as pearls. Japan and Australia are the largest producers of cultured pearls, though Fiji also produces some. See also pearl.

* * *

Universalium. 2010.

Игры ⚽ Нужно сделать НИР?

Look at other dictionaries:

  • cultured pearl — cultured pearls N COUNT A cultured pearl is a pearl that is created by putting sand or grit into an oyster …   English dictionary

  • cultured pearl — n. a pearl grown within a mollusk by controlled stimulation, as by insertion of a bead of mother of pearl …   English World dictionary

  • cultured pearl — n a ↑pearl that has been grown artificially …   Dictionary of contemporary English

  • cultured pearl — noun count a type of PEARL grown artificially, instead of that grows in an OYSTER …   Usage of the words and phrases in modern English

  • Cultured pearl — A newly opened Hyriopsis cumingi, freshwater mussel, showing the rows of cultured pearls inside. A cultured pearl is a pearl created by a pearl farmer under controlled conditions. Development of a pearl A pearl is formed when the mantle tissue is …   Wikipedia

  • cultured pearl — noun also culture pearl : a natural pearl grown under controlled conditions (as by inserting a seed pearl into the mantle of an oyster and keeping the oyster in a sea bed for some years) * * * a pearl induced to form by placement of a grain of… …   Useful english dictionary

  • cultured pearl — UK / US noun [countable] Word forms cultured pearl : singular cultured pearl plural cultured pearls a type of pearl grown artificially, instead of one that grows naturally in an oyster …   English dictionary

  • cultured pearl — cul′tured pearl′ n. jew a pearl induced to form by placement of a grain of sand or another irritating object within the shell of a pearl oyster or mussel • Etymology: 1920–25 …   From formal English to slang

  • cultured pearl — noun (C) a pearl (1) that has been grown artificially …   Longman dictionary of contemporary English

  • cultured pearl — /kʌltʃəd ˈpɜl/ (say kulchuhd perl) noun a pearl grown around a speck of foreign matter artificially introduced into the shell of an oyster or clam …  

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”